Solar Regulator and Shunt

Jakachira
Jakachira Solar Expert Posts: 47 ✭✭
Hi, guys. I read some heated debate about the SOC monitoring done by Steca PR regulators. I do have one.

To start, Steca docs state that the controller monitors the state of charge of a battery accurately only when there is no discharge or charging source connected directly to the battery. Now the problem is many people use inverters which cannot be connected to the Load connection under normal circumstances. One has to connect to the battery directly thereby rendring the SOC display of the controller invalid.

So this guy was asking if its possible to use a shunt to monitor these alien dis/charge connections at the the battery terminals?

How do you use a shunt? and What is the use of it? How can one connect it with a regulator like this to monitor every current going in and out of the Battery?

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Thanks

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Solar Regulator and Shunt

    First off, one should never connect an inverter to any charge controller's "LOAD" terminals. They should always be connected to the battery bank. And don't forget the fuse!

    Second, a shunt doesn't monitor anything. It is a "known, fixed resistance" that is temperature stable. It is used in conjunction with a battery monitor - http://store.solar-electric.com/metersmonitors.html - to get a fairly accurate picture of how much current is going in/out of the batteries and what the real State Of Charge is.

    Otherwise, all charge controller meters (not just Steca) only show the power going from the controller to the batteries - they have no way of detecting what is being drawn back out at the other end. The accuracy of said meters is another topic of debate, as they all are subject to certain design characteristics which make them less than 100% true. Most of the time this is not a worry.

    Did that help? :D